In general, a small-sized camera module is mounted in a mobile terminal such as a smartphone. In such a camera module, a lens driving device is employed (for example, PTL 1). The lens driving device has an auto-focusing function of automatically performing focusing for capturing a subject (hereinafter referred to as “AF (Auto Focus) function”), and a shake-correcting function (hereinafter referred to as “OIS (Optical Image Stabilization) function”) of optically correcting shake (vibration) upon capturing an image to reduce the irregularities of the image.
A lens driving device having the auto-focusing function and the shake-correcting function includes an auto-focusing driving part (hereinafter referred to as “AF driving part”) for moving the lens part in the light axis direction, and a shake-correcting driving part (hereinafter referred to as “OIS driving part”) for swaying the lens part in a plane orthogonal to the light axis direction.
The AF driving part includes, for example, an auto-focusing coil part (hereinafter referred to as “AF coil part”) disposed at a periphery of the lens part, an auto-focusing magnet part (hereinafter referred to as “AF magnet part”) separated from the AF coil part in the radial direction, and an elastic supporting part (for example, a leaf spring) configured to elastically support an auto-focusing movable part (hereinafter referred to as “AF movable part”) including the lens part and the AF coil part with respect to an auto-focusing fixing part (hereinafter referred to as “AF fixing part”) including the AF magnet part for example. Automatic focusing is performed by moving the AF movable part in the light axis direction with respect to the AF fixing part by utilizing a driving force of a voice coil motor composed of the AF coil part and the AF magnet part. It is to be noted that the AF fixing part may include the AF coil part, and the AF movable part may include the AF magnet part.
The OIS driving part includes, for example, a shake-correcting magnet part (hereinafter referred to as “OIS magnet part”) disposed in the AF driving part, a shake-correcting coil part (hereinafter referred to as “OIS coil part”) separated from the OIS magnet part, and a supporting part configured to support a shake-correcting movable part (hereinafter referred to as “OIS movable part”) including the AF driving part and the OIS magnet part with respect to a shake-correcting fixing part (hereinafter referred to as “OIS fixing part”) including the OIS coil part. Shake correction is performed by swaying the OIS movable part in a plane orthogonal to the light axis direction with respect to the OIS fixation part by utilizing a driving force of a voice coil motor composed of the OIS magnet part and the OIS coil part (so-called barrel shift system). The OIS magnet part can also serve as the AF magnet part, and with such a configuration, the size and the height of the lens driving device can be reduced. In addition, a suspension wire is employed as a supporting part for supporting the OIS movable part with respect to the OIS fixing part, for example.